1. Field of the Invention
This invention relates in general to multi-channel audio production, editing and playback systems.
2. Description of Related Art
As with light sources, sound sources possess a spectral signature. Recent research has revealed the non-periodic nature of many acoustical waveforms, despite the preponderance of observable fundamentals and harmonics. The spectral signatures of real-world sound sources have been shown to change over time, particularly when it is viewed in terms of decay and reflection through boundaries. However, current sound reproduction systems have proved inadequate in the characterization of sound sources which are, by nature, dynamic entities.
With the continuing evolution of digital audio technology, breakthroughs seem to be commonplace in sound reproduction methods. In truth, however, it is not really possible to introduce real innovation into audio entertainment without controlling the recording/playback chain. This is quite significant since it is well known in high-end consumer audio circles that the truly difficult task in the design of audio equipment is not the creation of sound stage depth, but rather, the realistic and accurate preservation of horizontal and vertical location of objects and events.
Careful attention to the phase response of the reproduction chain can do much to resolve the perceived depth of a recording. The "distance back" aspect of reproduction requires the preservation of very subtle timing relationships within the recorded material, often as small as microseconds. As a design task, this is less difficult to execute than to project the more complex and subtle cues that convey XY plane location and "vaulting" ambience. The accurate re-creation of the true ambient "feel" of a real-world sonic event requires the neutral transfer of a great amount of information, i.e., electronically encoded cues that, when replayed, provide the illusion of "liveness".
The preservation of the subtle minutiae that convey accurate spacing and size of the recorded events is also important. In a channel reproduction system, this is exceedingly difficult to do. On the production side, the illusions of XY plane location, and even size and space, are projected by means of ingenious but often tortuous production techniques. For example, the continued development of surround sound technology extends and enhances these methods. Still, these techniques are attempts to ameliorate problems inherited from earlier, more primitive technology. In any case, the efforts are largely wasted in that the vast majority of venue playback systems lack even rudimentary elements of good sonic designs.